359
Floating-point Math Instructions
Section 5-24
Flags
ER:
Indirectly addressed EM/DM word is non-existent.
(Content of
*
EM/
*
DM word is not BCD, or the EM/DM area boundary
has been exceeded.)
ON if the multiplicand or multiplier data is not recognized as floating-
point data.
EQ:
ON if both the exponent and mantissa of the result are 0.
OF:
ON if the absolute value of the result is too large to be expressed as a
32-bit floating-point value. (The result will be output as
±∞
.)
UF:
ON if the absolute value of the result is too small to be expressed as a
32-bit floating-point value. (The result will be output as 0.)
5-24-8 FLOATING-POINT DIVIDE: /F(––)
Limitations
The Dividend (Dd+1 and Dd) and Divisor (Dr+1 and Dr) data must be in
IEEE754 floating-point data format.
DM 6143 to DM 6655 cannot be used for R.
Description
When the execution condition is OFF, /F(––) is not executed. When the execu-
tion condition is ON, /F(––) divides the 32-bit floating-point number in Dd+1
and Dd by the 32-bit floating-point number in Dr+1 and Dr and places the
result in R+1 and R. (The floating point data must be in IEEE754 format.)
If the absolute value of the result is greater than the maximum value that can
be expressed as floating-point data, the Overflow Flag (SR 25404) will turn
ON and the result will be output as
±∞
.
If the absolute value of the result is less than the minimum value that can be
expressed as floating-point data, the Underflow Flag (SR 25405) will turn ON
and the result will be output as 0.
Dd
:
First dividend word
IR, SR, AR, DM, EM, HR, TIM/CNT, LR
Dr
:
First divisor word
IR, SR, AR, DM, EM, HR, TIM/CNT, LR
Ladder Symbols
Operand Data Areas
R
:
First result word
IR, SR, AR, DM, EM, HR, LR
/F(
−−
)
Dd
Dr
R
@/F(
−−
)
Dd
Dr
R
R+1
R
Dd
Dividend (floating-point data, 32 bits)
Dd+1
Dr
Divisor (floating-point data, 32 bits)
Dr+1
Result (floating-point data, 32 bits)
÷
